ORIGINAL: DarZeelon
It is said that the added clearance, in C3 bearings, allows crankshaft wobble to damage the seal between the crankshaft and the surrounding crankcase, in the front port area.
Use C3 only if the original was C3, or if you double your horsepower. Even a tuned pipe will not make it necessary.
Dave,
But I did say it...
Not the same words, maybe, but factually the same.